一、窗口处理函数

LRESULT CALLBACK WindowProc(
  HWND hwnd,      // handle to window
  UINT uMsg,      // message identifier
  WPARAM wParam,  // first message parameter
  LPARAM lParam   // second message parameter
);

二、窗口类

typedef struct _WNDCLASS { 
    UINT       style; 
    WNDPROC    lpfnWndProc; 
    int        cbClsExtra; 
    int        cbWndExtra; 
    HINSTANCE  hInstance; 
    HICON      hIcon; 
    HCURSOR    hCursor; 
    HBRUSH     hbrBackground; 
    LPCTSTR    lpszMenuName; 
    LPCTSTR    lpszClassName; 
} WNDCLASS, *PWNDCLASS; 

ATOM RegisterClass(
  CONST WNDCLASS *lpWndClass  // class data
);

三、创建窗口

HWND CreateWindow(
  LPCTSTR lpClassName,  // registered class name
  LPCTSTR lpWindowName, // window name
  DWORD dwStyle,        // window style
  int x,                // horizontal position of window
  int y,                // vertical position of window
  int nWidth,           // window width
  int nHeight,          // window height
  HWND hWndParent,      // handle to parent or owner window
  HMENU hMenu,          // menu handle or child identifier
  HINSTANCE hInstance,  // handle to application instance
  LPVOID lpParam        // window-creation data
);

四、消息循环

while(GetMessage( &msg, NULL, 0, 0 ))
{ 
    TranslateMessage(&msg); 
    DispatchMessage(&msg); 
}